To characterize the quality and performance of a mobile phone network, a mobile phone is conventionally placed in a suitable test device and brought into different locations within the network. At each location, the quality of communication is tested and logged. Similar test devices can also be used to test the quality of a mobile phone.
While in the test device, the phone is typically powered by a “dummy battery”, which replaces the normal battery unit of the phone and is connected to an external power source. The “dummy battery” simulates the behavior of the phone's normal battery unit. This allows to interrupt the power supply to the phone in order to reset it in case of malfunction. This scheme becomes, however, more and more difficult because modern battery units are complex and therefore difficult to simulate.